Re: [PATCH] alpha: correct handling of negative *rlimit() args besides -1

[Carlos O'Donell <carlos@redhat.com>]

On 10/7/22 22:45, Matt Turner via Libc-alpha wrote:
> The generic version of RLIM_INFINITY in Linux is equal to (rlim_t)-1,
> which is equal to ULLONG_MAX.  On alpha however it is instead defined as
> 0x7ffffffffffffffful.  This was special-cased in 0d0bc78 [BZ #22648] but
> it specifically used an equality check.
> 
> There is a cpython test case test_prlimit_refcount which calls
> setrlimit() with { -2, -2 } as arguments rather than the usual -1, it
> therefore fails the equality test and is treated as a large arbitrary
> positive value past the maximum of RLIM_INFINITY and fails with EPERM.
> This patch changes the behavior of the *rlimit() calls to treat all
> integers between 0x7ffffffffffffffful and (rlim_t)-1 as (rlim_t)-1,
> i.e., RLIM_INFINITY.
> ---
>  sysdeps/unix/sysv/linux/alpha/getrlimit64.c | 4 ++--
>  sysdeps/unix/sysv/linux/alpha/setrlimit64.c | 4 ++--

Is MIPS affected by the same problem?

>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/alpha/getrlimit64.c b/sysdeps/unix/sysv/linux/alpha/getrlimit64.c
> index c195f5b55c..40f3e6bdff 100644
> --- a/sysdeps/unix/sysv/linux/alpha/getrlimit64.c
> +++ b/sysdeps/unix/sysv/linux/alpha/getrlimit64.c
> @@ -38,11 +38,11 @@ __old_getrlimit64 (enum __rlimit_resource resource,
>    if (__getrlimit64 (resource, &krlimits) < 0)
>      return -1;
>  
> -  if (krlimits.rlim_cur == RLIM64_INFINITY)
> +  if (krlimits.rlim_cur >= OLD_RLIM64_INFINITY)
>      rlimits->rlim_cur = OLD_RLIM64_INFINITY;
>    else
>      rlimits->rlim_cur = krlimits.rlim_cur;
> -  if (krlimits.rlim_max == RLIM64_INFINITY)
> +  if (krlimits.rlim_max >= OLD_RLIM64_INFINITY)
>      rlimits->rlim_max = OLD_RLIM64_INFINITY;
>    else
>      rlimits->rlim_max = krlimits.rlim_max;
> diff --git a/sysdeps/unix/sysv/linux/alpha/setrlimit64.c b/sysdeps/unix/sysv/linux/alpha/setrlimit64.c
> index 421616ed20..4e88540a48 100644
> --- a/sysdeps/unix/sysv/linux/alpha/setrlimit64.c
> +++ b/sysdeps/unix/sysv/linux/alpha/setrlimit64.c
> @@ -35,11 +35,11 @@ __old_setrlimit64 (enum __rlimit_resource resource,
>  {
>    struct rlimit64 krlimits;
>  
> -  if (rlimits->rlim_cur == OLD_RLIM64_INFINITY)
> +  if (rlimits->rlim_cur >= OLD_RLIM64_INFINITY)
>      krlimits.rlim_cur = RLIM64_INFINITY;
>    else
>      krlimits.rlim_cur = rlimits->rlim_cur;
> -  if (rlimits->rlim_max == OLD_RLIM64_INFINITY)
> +  if (rlimits->rlim_max >= OLD_RLIM64_INFINITY)
>      krlimits.rlim_max = RLIM64_INFINITY;
>    else
>      krlimits.rlim_max = rlimits->rlim_max;


-- 
Cheers,
Carlos.